heitlinger



Jan. 3, 1956 E. v. HEITLINGER ZEROIZING CONTROL MECHANISM 5 Sheets-Sheet1 Filed May 16, 1952 INVEN TOR. e/ze Wkd/z'rzqer' punk) diiornqys Jan.3, 1956 E. v. HEITLINGER ZEROIZING CONTROL MECHANISM 5 Sheets-Sheet 2Filed May 16, 1952 INVENTOR. Vfieiilzlzger flilomze gs Eugene Jan. 3,1956 E. v. HEITLINGER ZEROIZING CONTROL MECHANISM 5 Sheets-Sheet 3 FiledMay 16, 1952 a 3, 1956 1;. v. HEITLINGER 2,729,393

ZEROILING CONTROL MECHANISM Filed May 16, 1952 5 Sheets-Sheet 4 IN V ENTOR.

Eugene VjkizZzkzyer Jar-3% M 2,729,393 ZEROIZING CONTROL MECHANISMEugene V. Heitlinger, Franklin Park, lll., assignor to Felt and TarrantManufacturing Company, Chicago, lll., a corporation of IllinoisApplication May 16, 1952, Serial No. 288,133 23 Claims. (Cl. 235-430):lhis invention relates in general to calculating machines, and has asaccumulator of a lation of a digit key or keys.

. another important object of the invention is the pro- A furtherimportant object is to provide a control member selectively movable froma normal to an operative position to condition such zeroizing controlmeans by causing the same to be moved from its inoperative to its activeposition, and to effect return of said zeroizing con trol means toinoperative position from either its active or operated positions inresponse to return of such control member to normal position to enableoperation of the accumulator zeroizing mechanism, regardless of whetheror not any digit keys have been mismanipulated or whether or not anymismanipulated keys have been correctively actuated.

So-cailed split accumulator mechanism has been provided heretofore, bothin key-operated and key-responsive calculating machines, which may berendered operative to of the accumulator, such as the left half thereof,while not afiFecting the usual zeroizing of the remaining portion of theaccumulator, thus facilitating accumulation of a series of sub-totals inthe latter portion of the accumulator and a grand total in the left halfthereof, obtained by serial transfer of each sub-total to the leftportion of the machine and operation of the accumulator zeroizingcontrol member to clear the remaining portion of the accumulator foraccumulation of the next sub-total. It was noted that errors could goundetected under certain circumstances with such mechanism, which led tothe instant invention. Supposing the last digit key or keys (if morethan one were depressed simultaneously) were mismanipulated, orpartially depressed and released, in entering a sub-total in thelefthand portion of such a machine. The usual error control mechanismwould be activated to lock up the keyboard, except the mismanipulatedkeys, but the machine operator normally would immediately actuate thezeroizing control member to clear the right-hand portion of theaccumulator to condition the machine for computing the next sub-total.And such actuation of the zeroizing member would clear or de-activatethe error control mechanism,

so that an erroneous grand total would 2,729,393 Patented Jan. 3, 1956remain in the left portion of the accumulator without the operator beingaware of having made such an error.

An important object of the instant invention, therefore, is to eliminateany possibility of such errors occurring during such use of a splitaccumulator calculating machine.

More specifically, the object of this invention, as applied to such asplit accumulator machine, is to prevent actuation of the accumulatorzeroizing member, whenever the machine is set for split accumulator useand a digit key is mismanipulated in entering a sub-total in the leftportion of the accumulator, and until either the mismanipulated key orkeys have been correctively actuated, or the split accumulator mechanismhas been inactivated.

Numerous other objects and advantages of the invention will be apparentas it is better understood from the following description, which, whentaken in connection with the accompanying drawings, discloses apreferred embodiment thereof.

In the drawings:

Figure 1 is a longitudinal, vertical section taken through akey-responsive calculating machine, in which a preferred embodiment ofmy invention has been incorporated, on a plane to the right of thelowest denominational order or column of digit keys, as viewed from theleft side of the machine, with certain of the conventional parts omittedfor purposes of clarity, and showing a portion of the instant zeroizingcontrol mechanism in normal inoperative or inactive position;

Fig. 1a is a detail view similar to Fig. 1, showing a portion of thezeroizing control mechanism in operated or blocking position;

Fig. lb is a view similar to Fig. 1a, showing these same parts in theiractive or operative positions;

Fig. 2 is a longitudinal, vertical section, similar to Fig.

l, on a plane ad acent an intermediate column of digit keys;

Fig. 3 is a similar sectional view on a plane to the left of the highestdenominational order of the machine, showing another portion of theinstant zeroizing control mechanism in normal inoperative or inactiveposition in full lines and in active or operative position in brokenlines;

Fig. 3a is a detail view similar to Fig. 3, with those parts of theinstant zeroizing control mechanism illustrated being shown in theiractive or operative positions;

Fig. 4 is a detail vertical section adjacent one of the highestdenominational orders, as viewed from the left side of the machine,showing portions of the usual error control mechanism and of my novelzeroizing control mechanism in normal position;

Fig. 4a is a detail perspective view of the rear end of one of thezeroizing detent actuator lifters and its stop bar engaging book, asseen from the right front corner of the machine;

Fig. 5 is a detail horizontal view, as seen from the line 5-5 of Fig. 4;

Fig. 6 is a vertical section similar to Fig. 4, with the illustratedparts of the error and zeroizing control mechanisms shown in theiroperated positions;

Fig. 7 is a detail horizontal section taken substantially on the line7-7 of Fig. 4;

Fig. 8 is an enlarged detail perspective view of a portion of thezeroizing detent actuator and one of the lifter hook wipers;

Fig. 9 is a skeleton plan view of part of the instant zeroizing controlmechanism; and

Fig. 10 is a detail transverse section taken substantially on the line10-40 of Fig. 4.

Referring more particularly to the drawings, the present invention isillustrated for convenience as being incorporated in the power driven,key-responsive calculating t me;

machine of the type known commercially as a Comp tometer and morespecifically described in United States Letters Pa n s o- 371 95 date Mach .5 1.9 1

an 11 ,195'1, ssued June 3, 1952, as Patent No. 2,599,257,

As in Patent No. 2,063,962, the calculatin machine h ein. us a d ambodyin he instant n nti ha s was lfllme iti s h u ed, in a uitab c in vand mounted on main skeleton frame members 22 (Figs; 1 and 9) andintermediate skeleton 'frarne memhers or a i iqn Pl te 2 d q sdbtitween.v e ac u mechanisms of the several denominational orders andsecured together in Sp ced relationship at suitable points by tie-rods24 (Figs. 1 and lb). A plurality of digit keys 25 (Fig. 2) are adaptedfor manipulation for determining the digital degree of the adding orcalculating movements of the machine and are arranged in the usualmanner in a plurality olum s, den m at na orders, only one of which isillustrated herein. Each such order of digit keys 25 is adapted tocontrol the digital aetuation of the associated denominational order ofa multi-denominational order accumulator. Upon depresn of an di t k y 5nd t k s e ,6; power is supplied from a power shaft 21 to extend anactuator spring 28 associated with the particular denominational orderof mechanism with which the depressed key is identified, release of thisspring thereafter accomplishing add n ms nt n a am u de rm e y. e Paiwlarj keydepressed h he a en y f ar. See tor or asegment 29, Each gearsector 2 9. mesheswith. a transmitting pinion or accumulator actuatinggear 31 (h s; q at b mo n e on a t t on y, rse. shaft 30 which isjournaled in the several skeleton frame plates 23. Each denominationalorder of the accumulator alsoincludes a gear train (not shown) fortransmitting actuation of the pinion 31 toan associatednumeral wheelgear 36, such gear train being atall times in meshwith the numeral wheelgear 36 and being mounted in an auxiliary rockfrarne pivotally movableabout a stationary transverse shaft to detrain the same from actuatinggear 31 for zeroizir g of the accumulator. S e cured to each numeralwheel gear 36, andv rotatably mounted on a stationary transverse shaft37 is a numeral wheel 38. Carrying mechanism is provided in eachdenominational order of the accumulator for the purpose of imparting adigital unit of actuation thereto each time that a tens transfer is totake place from the next lower denominational order of the accumulator.Since this mechanism is fully disclosedand illustrated in Patent No.1,357,7 8, i i shtnet u s e e sa q epe t uc description herein.

Depression of any one of the digit. keys. 25 causes its stem 26 toengage a parallel motion bar 4 1 (Fig. '2) which is pivoted at the frontof the machine at 42andat the rear at 43 to levers 44 and 45,respectively, which levers are pivoted in turn upon cross shafts orrods46 extending through the partition plates 22 and 23. A link 47'ispivotally connected at 48 to the lever 44 and at 49 tothe lever 45.The bar 41, levers 44 and and the link 47 form part ofthis parallelmotion device, and are constructed and mountedas shown and described indetail;

in lfatent No. 2,063,962, Each of the gear or rack sectors 29 isarticulately connected to a hook 51 by a link 52 the through a yieldingclutch 53, the hook 51 and link 52 being articulately connected to asubstantially vertical guide member 54, which is pivotally mounted atits lower end on a suitable transverse shaft. Each gear sector 29 alsois articulately connected to a movement controlling or stop bar 55 by alink 56. A spring 57, which is attached to lever 45 and to a latchmember 58 carried by the bar 47, normally contributes towards holdingthe parallel motion device in elevated position, and also holds thelower end of latch member 53 in a forward position (to the right in Fig.2) for a purpose which will be explained presently. A dog 59, which ispivoted at its upper end on the parallel motion bar 41, is provided witha laterally extending lug on its lower end for engagement with ahorizontal shelf on a spring-lifted lever 61 pivotally mounted on theguide member 54 with the hook 51. The operation of these parts is suchthat, upon depression of a digit key 25', its stem 26 engages anddepresses the bar 41 to impart motion to the parallel motion device,which carries dog 59 downwardly to depress the lever 61. A springmounted on the pivot between the link 52 and the hook 51 engages thelever 61 and the hook to urge the rear end of the latter (left end inFig. 2-) downwardly, so that it will normally cause engagement of thehook 51 with a toothed wheel 62 upon depression of lever 61. The toothedwheel 62 is secured to the power shaft 27, which turns in acounter-clockwise direction, viewing Fig. 2. The engagement of the hook51 with the wheel 62 pulls the link 52 toward the rear of the machine,or toward the left viewing Fig. 2, which imparts downward motion to gearsector 29 through the yielding clutch 53. Forward motion is thusimparted to the digital control or stop bar 55 until one of several lugsprojecting laterally therefrom (Fig. 4) is stopped by the stem 26 of thedepressed digit key.

The rearward motion of book 51 and link 52 causes the guide arm 54 toswing in a counterclockwise direction from its normal position of Fig. 2to extend the spring 23; one end of which is connected to this guide armand the other end to a transverse shaft extending through the skeletonframe plates. The link 52 moves the rack sector 29- downwardly on anidle stroke in response to such swinging of the guide arm 54 and intoposition to impart an adding movement to the accumulator upon release ofthe hook 5'1 and contraction of the spring 23. The downward movement ofgear sector 29 is under the control of the digital stop bar 55 and thegear sector is halted when it has been moved downwardly the properdistance, enabling it upon return to impart the degree of digitaladvancement-to the adding mechanism which corresponds-to the particularkey 25 depressed. The yielding clutch 53- per-mits the continuation ofthe rearward movement of link- 52, after downward movement of the gearsectorhas been stopped, and until the end of the full power stroke andthe automatic release of the book 51 from the toothed wheel 62; Releaseof book 51 is accomplished automatically in each instance, after a setincrement ofaction has been imparted to the link 52, by the teeth of thewheel 62. Upon the return or upward stroke (the operative stroke) of thegear sector 29, the yielding-clutch 53permits relative movement of theparts in reverse direction-to that at the beginning of the addingmovement, and thereafter thisadding actuation is accomplished.

Latch member 53, which is pivotally mounted on link 47, is provided toprevent-return movement of the dog 59*before the hook'sl has beenengaged with the toothed whee1 62. This latch member 58 has a downwardlyextending armatits'rearend which is adapted to engage upon a lateralprojection ofthe dog'59 to hold the dog down against upward returnmovement and also to hold the parallel motion device in depressedposition. As is describedinnetail in. Paten N 5.0 9 em n ofthehookffl,with the toothed wheel-62v doesnot take place until a digit key 25 hasbeen completely depressed,

result in the parallel motion' device being latched in depressedposition by the latch member 58. And .until the hook 51 is engaged withthe toothed wheel 62, forward motion of the stop bar 55 cannot takeplace, which is emphasized here because such forward motion of the stopbar is employed in connection with the instant invention, in a manner tobe described hereinafter. Following complete depression of a digit key25 and engagement of the hook 51 with the toothed wheel 62, the latchmember 58 is swung in a clockwise direction to release the dog 59. Thisis accomplished, just prior to the release of the hook 51, by a pin 63provided in an upwardly extending arm of the vertical guide member 54,which through its connection with the hook 51 has been carriedrearwardly, the pin 63 engaging a finger 64 of latch member 58 to swingthe latter in a clockwise direction to free the dog 59 so that theparallel device may be spring returned to normal raised position.

Thus actuation of the accumulator numeral wheels 38 is accomplished and,machines, means are comprising the as in all such provided for zeroizingthe accumulator when desired. The zeroizing mechanism herein illustratedis the same as that employed in the machine of Patent No. 2,599,257 andcompletely illustrated and described in Patent No. 1,357,748, the samereference numerals being employed here as are used therein to designatesimilar parts. As previously noted, the gear train interposed betweeneach transmitting pinion or gear 31 and its denominationally associatednumeral wheel gear 36 includes a carrying winding gear which storespower, during its actuation by gear 31, in a carrying spring foreffecting tens carrying transfers to the accumulator mechanism of thenext higher denomina' tional order, and such carrying springs areemployed to return the actuated numeral wheels 38 to zero position upondetraining of such gear trains from their transmitting pinions 31. Thisdetraining is accomplished by forwardly swinging the lower end of theauxiliary rock frame which supports the accumulator gear trains inresponse to manual actuation of an operating handle or zeroizing lever71.

As shown in Fig. 1, this zeroizing lever 71 is pivoted at its lower endon a zeroizing crank pivot stud mounted in the righthand side plate 22of the machine frame. A segment 72 is fixed upon the inner portion ofthe stud 70 and a link 73 is pivotally connected at its rear end to thesegment 72 and at its forward end (right end in Fig. l) to a dependinglever 74 that in turn is pivoted at 75 on the fixed frame. The lower endof the lever 74 is pivotally connected by means of a short link 76 withan arm 77 rotatably mounted upon a transverse shaft 78 that is journaledin the skeleton frame members 22 and 23. The upper portion of this arm77 is provided with a transversely extending face 79 adapted to engage asecond arm 80 secured to the shaft 73. When these parts are in theirnormal positions of Fig. 1, a short swinging movement of the zeroizinghandle 71 forwardly (to the right therein) will impart a rockingmovement to the shaft 78 in a clockwise direction, as viewed in thisfigure, Additional rocker arms 81 (Fig. 2) are fixed in spacedrelationship to each other on the transverse shaft 78' for rotationtherewith. These rocker arms 81 are pivotally connected with curvedlinks 82 having slotted shifting pivots upon a transverse shaft 83extending through the skeleton frame members, The rocking movementimparted to the shaft 78 by the above described forward swinging of thezeroizing handle 71 will result in forward movement of the curved links82 (to the right in Fig, 2) which effects the detraining movement of theswinging rock frame to accomplish a zeroizing of an accumulator, asfully set forth in Patent No. 1,357,748. As will be apparent from themore detailed description in that patent, the accumulator remains indetrained position upon release of the zeroizing handle 71 until the -sothat partial depression-and release of a digit key will .next subsequentactuation of the accumulator is initiated by depression of a digit key25. However, release of the zeroizing handle 71 will result in its beingreturned to the normal position of Fig. 1 by a spring 104 connectedbetween a rear point on the right-hand frame member 22 and the segment72.

The instant invention also makes .use of other old mechanisms forinitiating its zeroizing preventing function in response tomismanipulation or partial depression and release of any digit key 25.Illustrated in Figs. 2, 4, and 6 herein are those parts of the errorcontrol mechanism thus employed which are more fully shown and describedin Patents Nos. 2,018,933 and 2,224,203. These error control devicesrequire a full stroke to be given any digit key 25 depressed, so as toinsure proper operation of the accumulator as above described, lock upthe entire keyboard except that denominational order or those orders inwhich a digit key or keys have been mismanipulated, and thereafterprevent operation of any keys 25 in such orders following corrective andcomplete depression of said mismanipulated keys, all as specificallydisclosed in those patents. Such error control devices include in eachdenominational order of the machine a latch or dog 105 (designated byreference numeral 63 in Patent No. 2,224,203). This dog 105 is pivotedon the denominationally associated link 47 and a spring normally pressesa lip 106 (Fig. 4) of the dog upwardly into contact with the lower edgeof the link 47. A ratchet tooth 107 is provided upon the upper portionof a lever 108 pivoted at 109 in a bracket 111 which in turn is pivotedon a cross rod 112 extending through the skeleton frame plates of themachine. A spring 113 is attached to the lower end of lever 108 and to alever 114 (Fig. 2) which is pivoted at its lower end upon a cross rod115. Upon depression of any one of the digit keys 25 in thatdenominational order, the link 47 forming part of the parallel motiondevice is moved toward the right, as seen in these figures, and thelatch or dog 105 being carried by it moves with it and past the ratchettooth 107.

As previously described, as a digit key is released without fullyeffective depression, the forward movement of the link 47 will beincomplete, and spring 57 functions to return the parts toward theiroriginal position of Fig. 2 without accomplishing the calculatingoperation. A link 117 (Figs. 4 and 6) is pivoted at 118 to the upper endof the lever 108, and at its rear end to a downwardly extending arm 119which may be oscillated about a pivotal mounting or stud 121 on anadjacent skeleton frame member 23. The spring 113 tends to swing lever108 clockwise, viewing these figures, and to bring a detent 122, securedto the rear end of the link 117, into contact with a stop 123 (as shownin Fig. 4) to limit forward movement of the lever 108. If insufiicientdown stroke and release of a digit key occurs, dog 105 engages tooth 107and, through lever 108, moves link 117 rearwardly with link 47 from itsnormal position of Fig. 4 to the left to its actuated position of Fig.6.

Means are provided for moving the ratchet tooth 107 out of the path ofthe dog 105 if and when full key-stroke is accomplished. Each bracket111 is provided with a downwardly extending arm 124 (Fig. 2) which isdisposed across the path of movement of a lug 125 upon the link 52. Asthe parts near the end of the power stroke resulting from completedepression of a digit key 25, the

lug 125 engages the arm 124 and lifts the bracket 111 about its pivot112, carrying up the lever 108 to raise the ratchet tooth 107 above thelower edge of the link 47 and out of the way of the dog 105. The lever108 has a portion 126 which is adapted to engage above a shoul der 127on the lever 114 when the lever 108 is thus lifted by lug 125. Thislever 108 is held in such upper latched position until near the end ofthe return or power stroke, when a lug 128 on the link 47 engages theupper end of the lever 114 to disconnect it from the shoulder 126,

'thereb'y 'ar'ran'gingthe parts in the normal position of Figs. 2 and4'for the next calculating operation.

Another old mechanism which is made use of, in order to most readilyincorporate the instant invention into existing Comptorneter machines,is a linkage which is actuated by the zeroizing crank or handle 71 tooperate a polarity reversal switch. This linkage, as seen in Figs. 1,la, lb, and 9, comprises a rearwardly extending link 131 articulatelyconnected at its forward end in any suitable manner to the zeroizingsegment 72 and pivotally mounted at its rear end on a stud 132. The stud132 extends inwardly through link 131 (Fig. 9) and is carried by thelower end of a lever 133 which is pivotally supported at its upper endat 134 on the right hand machine frame member 22.

Some further additional old mechanism will now be described which isincorporated in the machine disclosed in Patent No. 2,346,601 and thatin Patent No. 2,599,257, the following reference numerals being the sameas those employed therein for designating similar parts. Patent No.2,346,601 illustrates significant-digit indicating means, a portion ofwhich is employed herein, as in the machine of No. 2,599,257, to actuatea split accumulator mechanism. As shown in Fig. 2, a link 171 and athree-armed 'bell crank lever 172 are operatively connected with each ofthe rocker arms 81 and curved links 82. Each link 171 is pivotallyconnected at its rear end at 173 to a rearward extension of one of thelinks 82 and is pivotally connected at its forward end at 174 to thelower end of one of the levers 172. Each lever 172 is so shaped andarranged as to straddle one of the links 82 and one. of the links 171,and is pivotally secured at opposite sides thereof on the transverseshaft 83. The rearwardly extending arm of each lever 172 is pivotallyconnected at 175 to an upwardly extending link 176, the upper end ofwhich is pivotally mounted on a transverse rod 177 which extends acrossthe machine through suitable enlarged apertures in the skeleton frameplates 23 adjacent and behind the numeral wheels 38. The rod 177 isswingably suspended from the numeral wheel shaft 37 by means of curvedlevers 178 which are pivotally connected at their lower ends to the rod177 and rotatably mounted at their upper ends on shaft 37. Clockwiserotation of the rocker arms 81 from their normal position of Fig. 2 inresponse to forward swinging of the zeroizing control member or handle71, as previously described, will result in counterclockwise rotation ofthe bell crank levers 172 about the shaft 83 to lower the links 176 fromtheir normal position of Fig. 2 which, in turn, will swing the rod 177to its position of Figs. 3 and 3a, since this rod is supported forarcuate movement by the levers 178 suspended from the numeral wheelshaft 37. In Patent No. 2,346,601 this forward swinging movement of rod177 is employed to reset the significant-digit indicating memberstherein illustrated but the latter are not shown herein since they formno part of the instant invention. However, this forward swinging of rod177 in response to forward actuation of the zeroizing handle 71 isemployed to actuate the split accumulator mechanism of Patent No.2,599,257.

The machine of Patent No. 2,599,257 employs a split accumulatormechanism comprising means selectively operable to prevent clearing ofsome of the numeral Wheels 38 upon subsequent operation of the zeroizinghandle 71, so that any values contained in such numeral wheels will beretained therein while the other numeral wheels in the accumulator willbe returned to zero position. Employing herein the same referencenumerals as are used in that patent, this means includes a zeroizing orsplit accumulator control member or key 3111 (Figs. 1 and 3) located atthe lower right-hand portion of the machine and pivotally connected atits lower end to the rear end or" a forwardly extending lever 302 (Fig.l). A spring 3133 is connected at its lower; end to the rearward portionof this lever 302 and at its upper end to the machine frame, and theforward end ofv the lever 302 is pivotally mounted upon the transverseshaft 83, so that the spring 303 normally maintains the control member3111 in its uppermost position, as seen in Fig. 1. The forward end oflever 302. is maintained on the shaft 83 by means of a suitable U-shapedretaining clip 305, the outer leg of which engages the lever 302, whileits inner leg engages the inner surface of the adjacent portion of therighthand main side frame 22. The upper end of the zeroizing or splitaccumulator control member 301 is provided with a suitable finger button306 which is aligned longitudinally of the machine with the similarfinger button provided on the zeroizing crank 71 to facilitate eitherserial or simultaneous operation of these two control members 301 and71.

The stem of control key 301 is provided with a forwardly extendingrecessed lug 367 (Fig. 3) and is cut away on its rear edge to define arearwardly extending horizontal shoulder or shelf 3118. A crank arm 309disposed adjacent the outer surface of the control key 301 is providedwith an inwardly extending arm on its rear end which rests upon, and issupported by, the shoulder or shelf 308. The forward end of this crankarm 309 is rigidly secured in any suitable manner to the right-handouter end of .a fiatted transverse control shaft 311 journaled insuitable apertures provided in the several skeleton frame plates 22 and23. The left end of this transverse shaft 311 (Fig. 9) is provided witha suitable slot for engagement by a spring washer or clip 312 which alsoengages the outer surface of the left-hand side frame 22 to retain theshaft 3111, together with the crank arm 309, in assembled relationship.The right-hand portion of this shaft 311 extends through the aperturedlug 307 of control'member 301, normally engaging a lower rearwardportion of the aperture or movement-limiting recess in this lug (asshown in Fig. 3) which comprises a vertical slot for limiting upwardmovement of the control member 301 by its spring 363 (Fig. 1). Theforward portion of the aperture in the lug 307 comprises a recesscommunicating with the vertical slot portion and shaped at its loweredge to engage the shaft 311 to retain the control member in itsoperative position when the latter is depressed thereto manually againstthe action of spring 303 and urged rearwardly to such operativeposition. The split accumulator mechanism also comprises a plurality ofdetent lever assemblages, each indicated generally by reference numeral315, mounted respectively in selected denominational orders of themachine for pivotal movement on a transverse shaft 316, and comprising arigid body portion and a coil spring having a forwardly extending,cam-shaped end 323 resting upon the transverse rod 177. The rigid bodyportion of each detent lever 315 has a rearward extension 325 whichoverlies the control shaft 311 and is spaced slightly upwardly therefromin the normal inoperative position of the detent shown in Fig. 2.

With the selectively operable manual control member 301 in its normalinoperative or raised position of Figs. 1 and 3, the crank arm 399 hasits inwardly extending rearward end resting upon the shoulder 3118 tomaintain the transverse control shaft 311 in its normal position ofFigs. 1,2 and 3. Downward and rearward swinging movement of the upperend of this zeroizing and split accumulator control member 301 to itsoperative position against the action of spring 303 will result in therearward end of crank arm 309 being lowered to its position of Fig. 3a,and such movement of crank arm 339 results in the flatted portion ofshaft 311 assuming a horizontal position, as therein illustrated.Subsequent forward swinging of the zeroizing crank or handle 71 from itsnormal position of Fig. 1, as previously described, will swing thetransverse rod 177 from its normal position, as shown in Fig. 2, to theoperative position illustrated in Figs. 3 and 3a. As has also previouslybeen described, this control rod 177 remains in such forward operativeposition upon release of the zeroizing handle 71 and return of thelatter to its normal position of Fig. 1 and until any one of the digitkeys 25 subsequently is depressed fully to effect an accumulativeactuation. Movement of the transverse rod 177 from its normal orinoperative position forwardly to its operative position of Fig. 3a thuswill result in lifting of the forward nose ends of all of the detentlevers 315 into engagement with an adjacent tooth of the associatednumeral wheel gears 36 through the agency of the forwardly extendingends 323 of the coiled springs of the several detent lever assemblages.However, if the transverse control shaft 311 is disposed in its normalor blocking position of Fig. 3 when such actuation of the zeroizinghandle 71 is effected, the resulting forward swinging of the transverserod 177 from its normal position of Fig. 2 to its operative position ofFig. 3 will result only in tensioning or lifting of the forwardlyextending ends 323 of the several detent lever springs, since engagementof the detent levers with their numeral wheel gears 36 will be preventedby contact of the rearwardly extending portions 325 of the detent leverswith the outer or full diameter of the transverse control shaft 311, asshown in Fig. 3. In other words, each time that the zeroizing handle 71is actuated to effect zeroizing of the accumulator, all numeral wheelsin the denominational orders having no detent lever 315 will be returnedto Zero position, and whether or not the numeral wheels 38 will bereturned to zero in those denominational orders of the accumulator inwhich detent levers 315 are provided, will depend upon the position inwhich the zeroizing or split accumulator control member 301 is disposed.However, if the control member 301 is in its operative or loweredposition so that shaft 311 is in its position of Fig. 3a, the detentlevers 315 will be moved to their blocking positions of this figure andre tained therein to prevent return of their associated numeral wheels33 to zero position.

Following operation of the zeroizing crank 71 with the control member301 in its operative or depressed position, depression of any one of thedigit keys 25 will effect re-engagement of all of the numeral wheel geartrains with their column actuators and return of the transverse rod 177rearwardly to its normal inoperative position of Fig. 2. This willenable the several detent levers 315 to be returned by gravity to theirnormal inoperative positions of Fig. 2, and subsequent actuations ofzeroizing handle 71 similarly will effect, or not effect, zeroizing ofthe numeral wheels in those orders in which detent levers 315 aredisposed, depending upon the particular setting of the zeroizing orsplit accumulator member 301.

As previously explained, all of the mechanism so far described herein isold in that type of calculating machine known commercially as aComptometer and illustrated and described in detail in the severalpatents and applications identified. Generally similar split accumulatormechanism also is disclosed in Patent No. 2,656,110, as specificallyembodied in a key-driven machine, although that mechanism likewise couldbe employed in a powerdriven, key-responsive machine. Similarly, thenovel mechanism of the instant invention hereafter disclosed, whileillustrated as incorporated in a power-driven machine, could just aswell be embodied in a key-driven machine. For example, the clockwisemovement (as seen from the left of the machine) of the rock bar 116 ofthe error control mechanism, in response to mismanipulation .of a digitkey, as disclosed in Patent No. 2,570,068, which mechanism isincorporated in a key-driven machine, could be employed to actuate theinstant zeroizing preventing mechanism, instead of the rearward rockingof an arm 119, as hereafter described, and the present zeroizingpreventing mechanism also could be employed in a calculating machine nothaving such split accumulator mechanism as hereinbefore disclosed, iffound to be desirable,

with the addition of a manual control member other than the splitaccumulator control key 301 to render the same optionally eflective inthe manner .now to be described.

As noted earlier, the basic concept of the instant invention is toprevent zeroizing of the accumulator immediately followingmismanipulation of a digit key or keys, so as to prevent a resultingerroneous accumulation being mistakenly taken as correct by the machineoperator. But for the present mechanism, such an error could easilyresult from mismanipulation of the digit key or keys last operated inentering a sub-total, in a machine equipped with split accumulatormechanism, followed by actuation of the zeroizing handle to clear thoseorders of the accumulator not including the zeroizing preventing meanspreviously described. With more specific reference to the illustratedmachine, depression of control member 301 to operative position rendersthe detents 315 operative to prevent zeroizing of those denominationalorders of the accumulator having such detents, upon subsequent operationof the zeroizing handle 71. Supposing these detents 315 to be present inthe left half of the accumulator, the latter will thus be split in themiddle, so that sub-totals may be obtained in the right half of themachine and subsequently accumulated in the left half to obtain grandtotals. If a digit key or keys are not fully depressed in entering asub-total in the left portion of such machine, the resulting locking upof the keyboard might be overlooked by the operator, since the normalprocedure is to immediately operate the zeroizing handle 71 to clear theright half of the accumulator, and such actuation of handle 71 wouldreset the error control mechanism to normal inactive condition.Therefore, there would be no way for the operator to be apprized of thefact that the grand total remaining in the left half of the accumulatorwas incorrect.

The instant invention, as embodied in such a machine, prevents any sucherrors from occurring by immediately preventing zeroizing of theaccumulator in response to mismanipulation of a digit key and untilcorrective and full depression of the mismanipulated key. Morespecifically, this function is attained by a positive blocking of thezeroizing handle 71 against movement and in response to mismanipulationof any digit key 25 in any selected denominational order, such as thosehaving the zeroizing preventing detents 315 of the split accumulatormechanism. Such blocking function is obtained by providing a zeroizingcrank detent, indicated generally by reference numeral 341, which is inthe form of a bell-crank pivoted on a suitable spacer mounted on anupper tie-rod 24 at the rear of the machine and intermediate therightmost skeleton frame plate 23 and the right-hand frame member 22(Figs. 1, 1a, 1b, and 9). This bell-crank 341 comprises a lower detentarm 342 extending rearwardly of the machine and terminating in a cutawayend portion to provide a shoulder 343 engageable with the linkage stud132 (Figs. 1a and 9), in a manner to be later described, and an uppercam arm 344 extending upwardly and forwardly and having a cam lug 345formed on its rear surface adjacent its upper end with upper and lowercontact faces. A spring 346 is connected between the lower por tion ofthe bell-crank detent 341 below its pivot 24 and a fixed point on themachine frame forwardly thereof to urge the detent in a counterclockwisedirection, as seen from the left side of the machine in Fig. l, I v

A zeroizing detent actuator 347 is provided which preferably is formedas a sheet metal angle member by stamping, or the'like, and extendstransversely across the upper rear portion of the machine (Figs. 1 and9), with its lower leg including a plurality of forwardly extending arms348, one for each denominational order or column and ex? tending intothe space between each pair of intermediate frame plates 23. The otheror upper leg of this angle member is provided with a plurality ofrearwardly and upwardly extending arms 349, one disposed to the right ofeach arm 348, to function as part of a corrective mechanism .to be laterdescribed. At each lateral end of the actuator 347 and secured totheinside surfaces 'of the 11 V angle defined thereby, preferably. bywelding, is a pivot sthd 3 51 extending beyond the ends of theactuator-and together defining a transverse and horizontal axis of rota-'tion' therefor. Right and left end female bearing supports are providedfor these male pivot studs 351, each of which "preferably comprisesascrew machine produced bearing member 352 having a blind hole at itsinner end for receiving a stud 351 and a shoulder at its outer endriveted to an auxiliary adapter or bearing plate 353. Each bearing plate353 is 'apertured to receive the usual screws for securing the ends ofthe two tie rods 24 shown in Fig. 1a, and are 'held' thereby against theouter surfaces of the main frame plates 22 (Fig. 9). Each bearing plate353 also has'a rearwardly extending finger 354 formed thereon, thaton'the left-hand bearing support being bent inwardly to extend through asuitable aperture in the frame plate 22 and be engaged by the outer endof a coil spring 355 of very light gauge wire loosely surrounding theleft-hand bearing member 352. The inner end of this spring 355 ishook-shaped to engage the left end of the Zeroizing detent actuator 347and urge the latter in a clockwise direction, viewing Fig. l, whichtends to lightly depress the forward arms 348.

' The forwardly extending leg of the actuator 347 also is provided atits right end (Fig. 9) with a forwardly extending cam arm 356longitudinally aligned with the zeroizing detent 341 and shaped at itsforward end to provide correct camming contact with the cam lug 345 asshown in Figs. 1; 1a and lb. Adjacent its left end (Figs. 3 and V 9),the actuator 347 has a forwardly extending arm 357 normally resting uponthe rear end of a Zeroizing detent actuator control lever 358 which isprovided adjacent this rear end with an upwardly and rearwardlyextending hook 359 overlying the arm 357, for a purpose to be laterdescribed. The control lever 358 extends towards the front of themachine in the usual overflow column, and is provided at its approximatelongitudinal center with an outwardly extending sleeve bearing 361rotatably mounted on a short transverse shaft 362. The latter is anadded shaft passed through existing apertures in the last two left-handskeleton frame plates 23 and is secured thereto in any suitable manner.The control lever 358 terminates at its forward end in a ramp-like shelfor cam surface 363 and is connected rearwardly of its pivot with a coilspring 364 urging its forward end upwardly. Normally, suchcounterclockwise movement (viewing Fig. 3) of lever 358 is blocked bycontact of a horizontally disposed portion of the cam surface 363 withthe lower end of a zeroizing detent actuator control lever arm 365mounted upon, and pinned to, the fiatted control shaft 311. This controlarm 365 is provided with a rearward extension 366 (Fig. 3a) connected tothe upper end of a spring 367, the lower end of which is hooked underthe forward cross shaft 46. The spring 367 urges control arm 365forwardly and also assists in rotating control shaft 311 from its normalposition of Fig. 3 to its actuated position of Fig. 3a, which results inmoving control arm 365 out of engagement with control lever 358.Resulting upward movement of the forward end of control lever 358 by itsspring 364 is limited by engagement of the control lever with theforward shaft 46.

Referring now to Figs. 4, 4a, 6, 7 and 10, the instant novel mechanismalso includes means, actuated by the old error control mechanism earlierdescribed, to move the zeroizing detent actuator 347 to effect blockingof the zeroizing handle 71 by the zeroizing detent 341. In the presentembodiment of the invention, this means comprises a zeroizing detentactuator lifter, indicated generally by reference numeral 368, one ofwhich is adapted to be inserted into each selected column ordenominational order of the machine, preferably each order of the lefthalf of the machine which is equipped with a split accumulator detentlever 315. Each lifter 368 comprises a, longitudinally extending armadjacent the left side of the right-hand skeleton frame plate 23 of thatpair of such intermediate frame plates defining the column ordenominational order with which this lifter cooperates. The lifter arm368 is provided near its forward end with a suitable bearing hub,preferably riveted thereto, which cooperates with a solid bearing point,comprising the existing stud 121 riveted to each intermediate framemember 23 and extending to the left thereof, as both a positioning and arotary bearing point for the main body of the arm. The arm 368 also isformed at its forward end with a reversely bent or rearwardly extendingportion 369 (Fig. 7) adapted to lie in back, or to the right, of anexisting headed stud 371 riveted to the intermediate frame plate 23.Just to the rear of its bearing hub, the arm 368 is provided with aright-angled shelf 372 extending to the right from its lower edge, theforward edge of which shelf rests against the rear edge of the arm 119of the error control mechanism previously described. The rear end of thelifter arm 368 underlies the denominationally associated, forwardlyextending arm 348 of the zeroizing detent actuator 347, and the lifter368 is so dimensioned that the rearward swinging movement of arm 119about its pivot 121 from its position of Fig. 4 to that of Fig. 6,resulting from a partial key stroke or mismanipulation of a digit key 25in that order, will be multiplied at the rear end of lifter arm 368 soas to move the actuator 347 through an are sufficient to accomplish itsrequired function.

As best seen in Fig. 4a, the rear end portion of lifter arm 368 isprovided with a right-angled, L-shaped shelf 373 and a stud 37 4 (Figs.4 and 10) preferably riveted to the arm and, with the shelf, extendingto the right thereof like shelf 372. A zeroizing detent actuator lifterstop bar hook 375 is provided with a suitable bearing hub rotatablymounted on the stud 374, and a coil spring 376 on this hub has itsopposite ends engaging the rear edges of the hook 375 and shelf 373 toresiliently maintain the lower end of the hook against the forward edgeof the shelf and between arm 368 and the outer leg of this shelf 373.The upper end of hook 375 is so shaped as first to be cammed rearwardlyby the stationary rear end of the laterally extending portion of itsdenorninationally associated stop bar 55 against the action of spring376, as the lifter 368 is swung upwardly from its position of Fig. 4,and upon completion of such lifting of arm 368,

then to be moved forwardly by spring 376 into its position of Fig. 6,wherein it is hooked over the rear end'of stop bar 55 to retain thelifter arm 368 in such actuated position.

Corrective mechanism is provided for removing the hook 375 from suchactuated position in engagement with its associated stop bar 55, in theevent that the operator returns the control member 301 to its normalraised position without first correctively actuating the mismanipulateddigit key. For convenience and simplification of design, such correctivemechanism also functions as blocking means for preventing retentiveengagement of hook 375 with its stop bar 55, in the event of a partialkey stroke occurring when the control member 361 is in its normal raisedposition. This corrective mechanism and blocking means comprises azeroizing detent actuator lifter hook wiper, indicated generally byreference numeral 377, one of which is provided in each column ordenominational order of the machine having a lifter 363 and hook 375(Figs. 2, 4, 5, 6, 8 and 10). Each of these wipers 377 is hung orpivotally mounted upon the spacer of the upper rear tie-rod 24 by meansof parallel hook or hub portions 378 and 379 which are joined by atransverse spacing member 381, the rocking axis or axis of rotation ofthe wiper being common to the axis of this tie-rod 24, and the wiperbeing loosely held against displacement from the tie-rod by the adjacentplate of the keyboard assembly (Fig. 2). As best seen in Figs. 8 and 10,each of the parallel hub or leg portions 373 and 379 has an outwardlyextending spacer lug 382 for engagement with the adjacent intermediateframe plate 23 to limit lateral movement of the wiper 377. The left-handhub portion 378 terminates at its rear in a downwardly extendingactuator leg 383 disposed forwardly of, and in contact with, the rear orupwardly extending leg of the zeroizing detent actuator 347. The rearportion of the right-hand hub member 379 similarly terminates in adownwardly and rearwardly extending cam arm or actuator leg 384 disposedrearwardly of, and in contact with, one of the upwardly extending reararms 349 of actuator 347. The forward portion of this hub member 379extends downwardly in the vertical plane of its rear leg 384 andterminates in a lateral wiper and blocking lug 385, the spacer lugs 382maintaining these members 384 and 385 in alignment, respectively, withtheir denominationally associated actuator arm 349 and litter hook 375,from front to rear of the machine.

Operation Operation of the old mechanism herein shown and to be foundmore in detail in the cited patents has been outlined in connection withthe preceding description of that mechanism. As incorporated in such amachine, the instant invention functions as follows. Whenever thecontrol member 301 is in its normal raised position of Figs. 1 and 3,the present zeroizing control or blocking mechanism remains inoperative.When computations are presented to the operator that may best beperformed by the use of the split accumulator mechanism, the zeroizingcontrol member 301 is depressed and set in operative position, aspreviously described. This results in the machine being dividedfunctionally from front to rear, so that the right half of theaccumulator subsequently may be zeroized without affecting any totalscontained in the left half of the accumulator, in response to operationof the zeroizing handle 71. Following accumulation of a sub-total in theright half of the accumulator, such subtotal is transferred to the lefthalf of the accumulator by the operator entering the same therein bydepressing the corresponding digit keys 25 in the proper left-handdenominational orders. If one or more of these digit keys aremismanipulated or only partially depressed and released, the instantmechanism functions to prevent subsequent operation of the zeroizinghandle 71, until either the mismanipulated digit key or keys have beencorrectively and fully depressed, or the control member 301 has beenretained to its normal raised position. Since the operator normallyactuates the zeroizing handle 71 fol lowing such transfer of a sub-totalfrom the right half of the accumulator to the left half thereof, he isthereby prevented from continuing the computations to obtain anothersub-total while leaving an incorrect grand total in the left half of theaccumulator. In other words, under such circumstancesif it were not forthe present zeroizing control mechanism, an erroneous accumulation wouldbe retained in the left half of the accumulator, since actuation of thezeroizing handle 71 normally clears the usual error control mechanism,which would permit the operator to continue with his computationsunaware of the fact that a digit key or keys had been incompletelyactuated in the preceding entry of a sub-total into the left half of theaccumulator.

Figures 1, 2, 3 and 4 illustrate the normal inoperative or inactiveposition of the various parts of the instant zeroizing controlmechanism. Upon depression of the control member 301 and setting thereofin its active position, these parts assume their active or operativeposi tions shown in full lines in Figs. lb and 3a and in broken lines inFigs. 3, 4, and 6. Depression of control member 301 results in rotationof control shaft 311 from its full line position of Fig. 3 to that ofFig. 3a to remove control arm 365 from engagement with the forward endof control lever 358. This enables spring 364 to swing the rear end ofcontrol lever 358 downwardly from its full line to its broken lineposition of Fig. 3 which, in turn, permits spring 355 to rotate thezeroizing detent actuoperated or blocking position of Figs. 6

ator 347 from its normal inoperative position of Fig. l to its active oroperative position of Fig. lb and as shown in broken lines in Figs. 3, 4and 6. In certain instances, as when control member 301 is depressedvery slowly, it has been found that zeroizing detent actuator 347 mightbecome hung up or remain in its normal inoperative position of Fig. 1following depression of control memher 301. That is why lever 358 hasbeen provided with its rearwardly extending hook 359 overlying the arm357, so that spring 364 then may insure proper setting of zeroizingdetent actuator 347 to its active oroperative position of Fig. 1b andprevent its remaining in normal inoperative position whenever controlmember 301 is depressed and regardless of the manner in which that isdone. So long as mismanipulation of a digit key 25 does not thereafteroccur in any of the denominational orders or columns comprising the lefthalf of the machine, the several parts of this zeroizing controlmechanism remain. in such second active or operative positions, andactuation of the zeroizing control handle 71 may be effected as desired.Immediately upon partial depression and release or mismanipulation ofany such digit key 25, however, the resulting rearward swinging of itsdenominationally associated arm 119 of the error control mechanism from.its normal position of Fig. 4 to its actuated position of Fig. 6 willresult in the rear end of the lifter 368 in that column being raised torotate the zeroizing detent actuator 347 in a counterclockwise directionto its full line, and la. Such movement of the zeroizing detent actuator347 from its second or operative position of Fig. lb to its third oroperated position of Fig. la causes its cam arm 356 to swing thezeroizing detent 341 into positive blocking engagement with thezeroizing linkage stud 132 to prevent operation of the zeroizing handle71. It will be noted that the arm 342 of this zeroizing detent 341 thushaving its shoulder 343 raised into the path of movement of the stud132, presents a solid bridge lock between this stud and the tie-rod 24upon which the zeroizing detent 341 is mounted, so that the zeroizingcrank 71 cannot be actuated even though heavy force is exerted thereon.The actuated zeroizing detent actuator lifter 368 is retained in suchposition, as shown in full lines in Fig. 6, by the resulting engagementof its hook 375 with the stop bar 55 in that order. It should also benoted that the rearwardly extending nose of hook 359 is spacedvertically a sufiicient distance above arm 357 when the parts are intheir second or operative positions, as shown in broken lines in Fig. 3,as not to prevent or interfere with such subsequent lifting or movementof zeroizing detent actuator 347 to its third or operated position shownin Fig. 1a and in full lines in Fig. 6.

It will be appreciated that in the normal inoperati e or inactiveposition of this zeroizing control mechanism, as shown in full lines inFig. 4, raising of the rear end of a lifter arm 368 in response tomismanipulation of a digit key in that denominational order will have noeffect upon the zeroizing detent actuator 347, since the associatedforwardly extending arm 348 thereon will be disposed above such raisedposition of arm 363 (that shown in Fig. 6). Also, raising of lifter arm368 under such circumstances will not effect engagement of the upper endof its hook 375 with the stop bar 55, as in the active operationabove-described, since the denominational associated wiper member 377will then be disposed in its normal position of Fig. 4, wherein its lug385 will be in blocking position to be contacted by the upper end of thehook 375 to prevent spring 376 engaging the hook with the stop bar 55.Consequently, the lifter 368 will be returned to its normal position ofFig. 4 either upon subsequent corrective actuation of the mismanipulateddigit key, or operation of the usual error control release but= ton orzeroizing crank 71.

With the control button 301 depressed, however, and followingmismanipulation of a digit key to bring the instant zeroizing controlmechanism to its position of Fig. 6, as above described, the actuatedlifter hook 375 will remain engaged with its stop bar 55 to retain thelifter arm 368 in such actuated position, despite return of the olderror control mechanism to normal position in response to actuation ofits lock release button, the wiper members 377 previously having beenmoved to clear the blocking lugs 385 forwardly of their blockingposition of Fig. 4 in response to the setting of control member 301 intoits operative position. It will be appreciated that suchcounterclockwise movement of the wiper members 377 (viewing Figs. 4 and6) will be effected by the rear, upwardly extending leg of actuator 347swinging the actuator legs 383 forwardly as actuator 347 moves from itsfull line to its broken line position of Fig. 4 in response todepression of control key 301. The actuator legs or cam arms 384 are soshaped that subsequent lifting of the actuator 34-7 from its broken lineto its full line position of Fig. 6, in response to actuation of lifterarm 368 following mismanipulation of a digit key, will not causemovement by their associated rear arms 349 of actuator 347 to return thelugs 385 to hook-blocking position, in response to such lifting of theactuator 347.

Any lifter hook 375 thus engaged with its stop bar 55 is releasedtherefrom to permit return of lifter arm 368 to its position of Fig. 4in either one of two ways. Usually, mismanipulation of a digit key (asabove described) having been signalled by the resulting locking of thezeroizing crank 71, the machine operator will proceed to correctivelyactuate the mismanipulated key or keys 25. This will result in theassociated stop bars 55 being moved forwardly from the position shown inFig. 6 as an incident to the resulting additive actuation of theaccumulator. The rear end of the stop bar 55 will thereby be moved outof engagement with its hook 375 to permit return of the lifter 368 toits normal position of Fig. 4. Such return of all of the displacedlifters 368 will enable spring 355 to rotate actuator 347 from its thirdor detent-blocking position of Fig. la to its second or active positionof Fig. lb, which will enable spring 346 to swing the arm 342 ofzeroizing detent 341 downwardly to its normal inoperative position. Thisis the usual manner in which the instant zeroizing control mechanism isreturned to such second or active position to enable subsequentoperation of the zeroizing crank 71. The other way in which the hooks375 that are engaged with their stop bars 55 (as shown in Fig. 6) may bedisengaged therefrom is in response to selective manual return of thecontrol memher 391 to its normal raised position of Figs. 1 and 3.

Such return of control member 301 includes lifting of arm 339 from itsposition of Fig. 3a to that shown in Fig. 3. This causes the lower endof control arm 365 to act upon cam surface 363 to return control lever358 to its normal, inoperative position of Fig. 3. The rear end of lever35% thereby lifts arm 357 to move actuator 347 from its third oroperated position of Fig. 1a to its first or normal inoperative positionof Fig. l, and the zeroizing detent 341 will thereupon be returned byits spring 346 to inoperative position to permit actuation of Zeroizingcrank 71. At the same time, the rear arms 349 of actuator 347 will bemoved from their full line position of Fig. 6 to that of Fig. 4 and, insuch movement, will actuate cam legs 38-: to rotate the wiper members377 in a clockwise direction from their position of Fig. 6 to that shownin Fig. 4. The lugs 385 function during such movement to Wipe the upperends of any lifter hooks 375 engaged with their stop bars 55 rearwardlyout of engagement therewith, which will permit the return of anypreviously actuated lifters 362 to their position of Fig. 4.

it will thus be seen that the zeroizing control mechanism normally isinoperative, and actuation of any of the lifters 363 in response tomismanipulation of a digit key in any denominationally associated orderof the machine will be ineffective to prevent operation of the zeroizingcrank 71. At the same time, the usual functioning of the old errorcontrol mechanism will not be affected. But upon setting of the controlmember 301 to operative position, the instant zeroizing controlmechanism is activated, so that subsequent mismanipulation of any digitkey in those columns or denominational orders containing the lifters 368will result in positive blocking of the zeroizing crank 71. However,mismanipulation of any digit key in any denominational order not havinga litter 363 obviously will not effect such operation of the instantzeroizing control mechanism, even though the latter be in its second oractivated position. Subsequent corrective actuation of all of themismanipulated digit keys will enable the operator to proceed with hiscomputations in a normal manner. Or if the operator desires to clear themachine and do the problem again from the beginning, it is necessaryonly to return the control member 3 to its normal raised position,whereupon the zeroizing crank 71 may be actuated. It will also beappreciated, as previously noted, that the instant zeroizing controimechanism is readily adapted for use with other types of error controlmechanism, such as that disclosed in Patent No. 2,570,068.. in suchenvironment, the lifters 3&8 would be arranged for movement by rock barof the error control mechanism of that patent following mismanipulationof a digit key. And, if desired, the instant zeroizing control mechanismalso may be employed in a machine which does not include the splitaccumulator mechanism herein disclosed merely by providing a controlmember settable to condition or activate the same, i. e., similar inthat function to the instant control member 391. And when applied to amachine in which corrective actuation of all mismanipulated digit keysmay completely reset the error control mechanism to normal and whichdoes not include a split accumulator mechanism, the present zeroizingcontrol mechanism could be maintained active at all times merely byeliminating the control lever 358 and any settable control membertherefor, whereby zeroizing or cancelling would be blocked whenever anydigit key was mismanipulated and until corrective actuation thereof. 7

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and it will beapparent that various changes may be made in the form, construction andarrangement of the parts without departing from the spirit or scope ofthe invention or sacrificing all of its material advantages, the formhereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A calculating machine, comprising anaccumulator, keys for controllingactuation of said accumulator, error control mechanism operable inresponse to mismanipulation of any of said keys to prevent erroneousactuation of said accumulator, means for zeroizing said accumulatorincluding a zeroizing control member, normally inoperative means incertain denominational orders of the machine for preventing zeroizing ofcertain denominational orders of said accumulator upon operation of saidzeroizing control member, selectively operable control means forrendering said normally inoperative means operable, and normallyinoperative mechanism in said certain denominational orders of themachine conditioned in response tooperation of said control means foractuation in response to subsequent operation of said error controlmechanism to prevent operation of said zeroizing control member.

2. In a calculating machine having a multi-denominational orderaccumulator, denominational columns of digit keys for controllingactuation of said accumulator, error control mechanism operable inresponse to mismanipulation of any of said keys to prevent erroneousactuation of said accumulator, means for zeroizing said accumulatorincluding a zeroizing control member, normally inoperative means incertain denominational orders of the machine for preventing zeroizing ofcertain of said denominational orders of said accumulatorupon operationof said zeroizing control member, and selective operable control meansfor rendering said normally inoperative. means operable; normallyinoperative mechanism in said certain denominational orders of themachine operable, when in active position, by said error controlmechanism in response to mismanipulation of any of said keys in saidcertain denominational orders of the machine to prevent subsequentoperation of said zeroizing control member; and means, operable inresponse to operation of said control means, for moving said normallyinoperative mechanism to active position to condition the same for suchoperation by said error control mechanism.

3. A calculating machine according to claim 2, including means operablein response to subsequent corrective actuation of all mismanipulatedkeys to return the operated said normally inoperative mechanism toactive position to enable subsequent operation of said zeroizing controlmember.

4. A calculating machine according to claim 2, including means, operablein response to return of said normally inoperative means to inoperativecondition by selective operation of said control means, to renderineflective said operation preventing function of said normallyinoperative mechanism to enable subsequent operation of said zeroizingcontrol member for zeroizing all denominational orders of saidaccumulator.

5. A calculating machine, comprising a multi-denominational orderaccumulator, denominational columns of digit keys for controllingactuation of said accumulator, normally inactive error control mechanismin. each denominational order of the machine activated in response tomismanipulation of any or the denominationally assoelated said keys toprevent erroneous actuation of said accumulator, means for zeroizingsaid accumulator including a zeroizing member operable to inactivatesaid error control mechanism, normally inoperative means in certaindenominational orders of the machine for preventing Zeroizing of certaindenominational orders of said accumulator upon operation of saidzeroizing member, selectively operable control means manually movablefrom normal position to render said normally inoperative means operable,normally inoperative mechanism in said certain denominational orders ofthe machine for preventing operation of said zeroizing member, and meansoperable by such movement of said control means for conditioning saidnormally inoperative mechanism for movement, in response to subsequentactivation of the denominationally associated said error controlmechanism, into blocking position to prevent operation of said zeroizingmember.

6. A calculating machine according to claim 5, wherein correctiveactuation of the mismanipulated keys inactivates said error controlmechanism, and means operable in response to such corrective actuationof the mismanipulated keys to move said normally inoperative mechanismfrom blocking position to enable operation of said zeroizing member.

7. A calculating machine according to claim 6, including means, operablein response to manual return of said control means to normal position,to return said normally inoperative mechanism to normal inoperativeposition.

8. A calculating machine, comprising an accumulator, digit keys forcontrolling actuation of said accumulator, normally inactive errorcontrol mechanism activated in response to mismanipulation of any ofsaid keys to prevent resulting erroneous actuation of said accumulator,mechanism for zeroizing said accumulator including a zeroizing memberoperable to inactivate said error control mechanism, normallyinoperative mechanism for blocking operation of said zeroizing member,and control means selectively operable manually from normal position tocause movement of said normally inoperative mechanism from a firstposition to a second position wherein said normally inoperativemechanism will be moved, in response to subsequent activation of saiderror control mechanism due to mismanipulation of any of said keys, to athird position to prevent operation of said zeroizing member.

9. A calculating machine according to claim 8, wherein correctiveactuation of the mismanipulated keys inactivates said error controlmechanism, and means operable in response to such inactivation of saiderror control mechanism to move said normally inoperative mechanism toits said second position to enable operation of said zeroizing member.

10. A calculating machine according to claim 9, including means operablein response to manual return of said control means to normal position tomove said normally inoperative mechanism from either said second orthird positions to its said first position.

l1. A calculating machine, comprising a multi-denominational orderaccumulator, denominational columns of depressible digit keys forcontrolling actuation of said accumulator, normally inactive errorcontrol mechanism activated in response to mismanipulation of any ofsaid keys to prevent resulting erroneous actuation of said accumulator,mechanism for zeroizing said accumulator includinga zeroizing member, anormally inactive zeroizing detent movable to active position to presenta solid bridge lock for preventing operation of said zeroizing member,normally inactive zeroizing control mechanism for moving said detent toactive position, and a manual control member selectively operable toactivate said zeroizing control mechanism for operation, in response tosubsequent activation of said error control mechanism due to partialdepression and release of any of said digit keys, to move said zeroizingdetent to active position.

12. A calculating machine, comprising a multi-denominational orderaccumulator, denominational columns of depressible digit keys forcontrolling actuation of said accumulator, normally inactive errorcontrol mechanism activated in response to mismanipulation of any ofsaid keys to prevent resulting erroneous actuation of said accumulator,mechanism for zeroizing said accumulator including a zeroizing member, anormally inactive zeroizing detent movable to active position to presenta solid bridge lock for preventing operation of said zeroizing member,normally inoperative zeroizing control mechanism movable from a firstinoperative position to a second operable position and to a thirdoperated position for moving said detent to active position, a manualcontrol member selectively operable between a normal inactive positionand an active position, and spring means for moving said zeroizingcontrol mechanism to said second operable position in response tomovement of said control member to active position, said zeroizingcontrol mechanism thereafter being moved to said third operatedposition, in response to subsequent activation of said error controlmechanism due to partial depression and release of any of said digitkeys, to move said zeroizing detent to active position.

13. A calculating machine according to claim 12, wherein said springmeans returns said zeroizing control mechanism to said second operableposition upon complete depression of said partially depressed andreleased digit keys, and a second spring means for thereupon moving saidzeroizing detent to inactive position to enable said zeroizing member tobe operated.

14. A calculating machine according to claim 13, including meansoperable upon movement of said control member to inactive position toreturn said zeroizing control mechanism from either said second or thirdpositions to said first inoperative position.

15. in a calculating machine having a multi-denominational orderaccumulator, denominational columns of digit keys for controllingactuation of said accumulator, error control mechanism operable inresponse to mismanipulation of any of said digit keys to preventerroneous actuation of said accumulator, mechanism for zeroizing saidaccumulator including a zeroizing member, normally inoperative splitaccumulator mechanism in certain denominational orders of the machinefor preventing zeroizing of said accumulator in said certain orders uponoperation of said zeroizing member to zeroize the remaining orders ofsaid accumulator, and a normally inoperative control member selectivelyoperable to render said split accumulator mechanism operative; meansreadily incorporable into said machine for operation by said errorcontrol mechanism in response to mismanipulation of any digit key insaid certain orders to prevent operation of said zeroizing member,comprising a normally inoperative zeroizing detent movable to operativeposition to block operation of said zeroizing member, a normallyinoperative transordinal detent actuator having an arm extending intoeach order of the machine, and detent actuator lifter means mountable ineach of said certain orders for actuating said arms in response tomismanipulation of a digit key in a denominationally associated column.

16. In a calculating machine according to claim 15, spring means urgingsaid detent actuator in a direction to lower said arms, and detentactuator control means normally retaining said detent actuator in afirst inoperative position against the action of said spring means andoperable in response to operation of said control member to permitmovement of said detent actuator by said spring means to a secondoperable position, said lifter means thereafter functioning in responseto mismanipulation of an associated digit key to move said detentactuator against the action of said spring means to a third operatedposition.

17. In a calculating machine according to claim 16, spring means urgingsaid detent into inoperative position, said actuator comprising meansoperable during movement thereof from said second to said third positionto move said detent positively to operative blocking position againstthe action of its spring means.

18. In a calculating machine according to claim 17, lifter retainingmeans for maintaining each actuated said lifter means in actuatedposition to restrain said detent actuator against spring-returnedmovement to said second position, said lifter retaining means beingdisabled in response to corrective actuation of the denominationallyassociated mismanipulated digit key.

19. In a calculating machine according to claim 18,

means operable in response to return of said control member to normalinoperative position to return said detent actuator from either saidsecond or third positions to said first position and to disable saidlifter retaining means.

20. In a calculating machine according to claim 19, means forming a partof said last-recited means for preventing effective operation of saidlifter retaining means While said detent actuator is in said firstinoperative position.

21. A calculating machine, comprising an accumulator, digit keys forcontrolling actuation of said accumulator, error control mechanismoperable in response to mismanipulation of any of said keys to preventresulting erroneous actuation of said accumulator, mechanism forzeroizing said accumulator, and zeroizing control mechanism operable inresponse to operation of said error control mechanism to blockinitiation of the operation of said zeroizing mechanism.

22. A calculating machine according to claim 21, wherein correctiveactuation of the mismanipulated keys inactivates said error controlmechanism, and means operable in response to such inactivation of saiderror control mechanism to return said zeroizing control mechanism tonormal position to enable operation of said zeroizing mechanism.

23. A calculating machine according to claim 21, wherein said zeroizingcontrol mechanism comprises a normally inoperative zeroizing detentmovable to opera tive position to block operation of said zeroizingmechanism, a transordinal detent actuator having an arm extend ing intoeach denominational order of the machine, and ordinal detent actuatorlifter means for actuating said arms in response to mismanipulation ofany digit key in a denominationally associated order.

References Cited in the file of this patent UNITED STATES PATENTS1,902,597 Turck Mar. 21, 1933 2,291,853 Webb Aug. 4, 1942 2,356,714 WebbAug. 22, 1944 2,389,062 Lambert Nov. 13, 1945 2,570,068 Niemann Oct. 2,1951 2,599,257 Heitlinger June 3, 1952

